Appliance for orthodontic treatment

ABSTRACT

This appliance comprises metal housings which are fastened by their base being glued to a defined tooth and of which those for the incisors, canines and premolars comprise a horizontal groove for receiving the arch wire, said groove issuing in the direction of the occlusal plane and being formed in an intermediate bridge connecting the base to an anterior wall, and ties, such as elastic rings, for tying the arch wire. 
     According to the invention, each of the housings for the incisors, canines and premolars comprises, for attaching an elastic ring for tying to the arch wire, and in the intermediate bridge, on one side, between the base and the groove for the arch wire, an anchoring flute issuing in the direction of the occlusal plane and, on the other side, between the base and the anterior wall, a horizontal groove issuing opposite the groove for the arch wire, while the anterior wall has a width and a height greater than those of the base and than those of the intermediate bridge, in order to mask this bridge and the elastic ring for tying the arch wire.

The invention relates, to an orthodontic dental appliance.

BACKGROUND OF THE INVENTION

In order to correct dental malformations both on the upper or maxillaryarch and on the lower or mandibular arch, it is known to use applianceswhich, within the framework of orthodontic treatment, make it possibleto straighten badly positioned teeth by imparting to them forces tendingto straighten them axially, that is to say in a lateral plane or under“torque”, that is to say in the anteroposterior plane.

Current appliances comprise, for each dental arch, housings or supports,also called brackets, which, glued to the inner or outer face of each ofthe teeth, comprise, as shown in the accompanying FIG. 1, on the onehand, a base b, in which is made a horizontal groove f capable ofreceiving an arch wire d which is composed of a nonoxidizing metal alloyand to which the base is connected by means of a tie consisting of aring of synthetic material or a metal wire.

Each housing is specific to a tooth, and the horizontal slots made inthe housings have an angulation relative to their base both in thefrontal vertical plane and in the anteroposterior vertical plane. Theseangulations vary as a function of the teeth on which the housings mustbe arranged and of the intended straightening. Likewise, the arch wiresare selected from a series of a plurality of arch wires differing fromone another in the morphology of the dental arches and, as regards eachdental arch, in the straightening forces which the branches provide. Inpractice, the metal arch wires have a more or less large round, squareor rectangular cross section and are modified as treatment progresses.

In a distalization phase of some teeth, the ends of the arch wire areconnected to means which impart to it a tensile force toward the rear,that is to say in the direction of the interior of the mouth, and aregenerated by external pericranial support means. As treatmentprogresses, the orthodontist adapts the force generated by the arch wireand those forces generated by possible intermaxillary connectionsbetween the maxillary corrective element and the mandibular correctiveelement, so as to adjust the repositioning of the teeth.

In some appliances, each arch wire is inserted horizontally into thegrooves of the housings fastened to the maxillary teeth and to themandibular teeth. Since each groove issues horizontally, the wire isheld insufficiently, this being conducive to the version or axialrotation of the teeth during treatment and consequently slowing down thecorrective effects of this treatment.

DESCRIPTION OF THE PRIOR ART

The same is true of appliances in which, as described in U.S. Pat. No.5,374,187 and U.S. Pat. No. 4,585,413, the horizontal groove forreceiving the arch wire is made in an intermediate bridge connecting thebase to an anterior wall and issues vertically in the direction of theocclusal plane or of the gum. This is because, if the connection to thearch wire is not firm, has play or is made punctually, it makes itpossible, under the straightening force imparted by the arch wire, forthe tooth to tilt by pivoting about the resistant center of the latter,said center being located midway up the root. During treatment, thetooth pivots in one direction and the other, generating, on the root,stresses which may lead to resorption, that is to say to a reduction inits length, and even to the loss of the tooth.

One object of the invention is to overcome these disadvantages byensuring a positive connection between housing and arch wire, making itpossible, by means of a low straightening force, to straighten the toothin a translational movement, or aggression, without any version of theroot.

With current appliances, it is necessary, in the distalization phase, tomake use of an extra-oral pericranial support appliance for generatingthe straightening forces on the arch wires. This solution is demandingfor the patient and, above all, because of its pericranial support,sometimes causes headaches which may have an adverse effect on cranialand basicranial structural growth, particularly in young patients atrisk who have disorders of the temporomaxillary joint or of vertebralstatics.

Another object of the invention is to provide an orthodontic appliancewhich avoids any need for extra-oral pericranial support tractions.

Another disadvantage of this current type of appliance is its unestheticnature, disclosed in FIG. 1. Specifically, even if each housingcomprises an anterior face composed of ceramic or the like of the colorof ivory, the metal arch wire forms a highly visible dark-colored girdlewhich attracts attention and mars the dental arch.

Likewise, the elastomeric ties connecting the housings to the arch wiresgradually add to the unesthetic appearance, since, under the action ofthe saliva, they swell, lose color and become yellow.

Another object of the invention is to provide an appliance which haslittle adverse effect on the esthetic appearance of the dental arches.

Finally, because of its uneven shapes, each housing promotes asubstantial retention of dental plaque both on its visible and on itsnonvisible parts. This dental plaque gives rise to risks of leucomas,coloration, enamel stains and even decay.

Another object of the invention is to reduce the formation of dentalplaque where it is formed and to make brushing easier.

SUMMARY OF THE INVENTION

The invention relates to an appliance which, for each in each casemaxillary and mandibular dental arch, is composed:

of a series of arch wires forming a U-shaped arc, surrounding eachdental arch and differing from one another in the straightening forceswhich their branches supply, said wires having a rectangular crosssection, with their small sides parallel to the occlusal plane,

of metal housings which are fastened by their base being glued to adefined tooth and of which those for the incisors, canines and premolarscomprise a horizontal groove for receiving the arch wire, said grooveissuing in the direction of the occlusal plane and being formed in anintermediate bridge connecting the base to an anterior wall, while thehousings for the molars comprise a tunnel for positioning the end of thecorresponding branch of the arch wire,

of ties, such as elastic rings, for tying the arch wire in the groovesof the housings,

and of means imparting, at least to the maxillary arch wire and in onetreatment phase, a tensile force directed toward the rear.

According to the invention, each of the housings for the incisors,canines and premolars comprises, for attaching an elastic ring for tyingto the arch wire and in the intermediate bridge, on one side, betweenthe base and the groove for the arch wire, an anchoring flute issuing inthe direction of the occlusal plane and, on the other side, between thebase and the anterior wall, a horizontal groove issuing opposite thegroove for the arch wire, while the anterior wall has a width and aheight greater than those of the base and than those of the intermediatebridge, in order to mask this bridge and the elastic ring for tying thearch wire.

By means of this appliance, the arch wires are inserted from theocclusal part toward the gingival part, thus making the practitioner'stask easier. The arrangement of the grooves for the elastic ringconsiderably improves the hold of the arch wires which can thus carryout more efficient dental correction, without unwanted movements.

The housings are very easy to clean, as are, moreover, the base and theintermediate bridge, since, where most of the housings are concerned,these parts are free of protuberances and various projections.

In esthetic terms, the anterior walls conceal from view not only thehousing, but also part of the arch wire and the ties of the arch wire tothe housing, thus doing away with the metallic appearance of currentappliances.

When the tie is put in place, it is concealed completely by the anteriorwall and therefore cannot, over time, impair the esthetic appearance ofthe appliance, for example by becoming yellow under the action ofsaliva.

In one embodiment, the tie formed by the elastic ring comprises twoloops surrounding the parts of the arch wire which projectlongitudinally from the intermediate bridge, and these loops areobtained as a result of the elastic ring being put in place around theintermediate bridge, in the flute and in the groove of the housing,then, after the introduction of the arch wire into the groove, of theelastic ring being pivoted around the arch wire for the purpose ofattaching its loop coming from the flute in the opposite groove.

By virtue of the two loops, the arch wire is wedged firmly in the groovein terms of vertical translation, horizontal translation andlongitudinal translation, so that the tooth cannot pivot relative tosaid arch wire and, under the straightening force, can be displaced onlyin a translational movement parallel to itself, without any effect onits root.

In one embodiment, and for carrying out the straightening of complexpathologies, each housing for the canines and premolars comprises, inits part between the base and its anterior part, a vertical well issuinginto the groove for the arch wire and forming, with a flute made in thebottom of said groove, an anchoring member for the bent end of one ofthe branches of a kickover spring for the axial straightening of thetooth, the other branch of this spring being provided with an end hookhooking onto the arch wire.

Thus, the straightening of a tooth by means of a housing of this type iscarried out by the kickover spring which comes to bear with one of itsbranches on the arch wire and, by its other branch cooperating with theintermediate bridge, imparts the axial straightening force to thehousing and therefore to the tooth to which this housing is fastened.

In one embodiment, the appliance comprises a maxillary arch wire for thebilateral distalization of the molars and canines, comprising, on eachof its lateral branches, on the one hand, a helical spring which isarranged around said branch and the anterior end of which is connectedto this branch by means of a weld arranged on a zone of this branchwhich is set back from the canine, while the posterior end of thisspring comes to bear on the housing of a molar, and, on the other hand,a vertical hook which, projecting upward from a part of the branch whichcomes between the lateral incisor and the canine, forms an attachmentmeans for one of the ends of an elastic intermaxillary traction ring,the other end of which is attached to a gingival hook projecting fromthe housing fastened to the first mandibular molar.

This device, used in a first therapeutic stage, makes it possible todispense with any other means for putting the arch wire under tractionand, in particular, with the pericranial support means. Said device iseasily inserted between the gums and the cheeks and, by virtue of thegood connection between the arch wire and the grooves of the housingssubjected to stress, makes it possible to reduce the straightening time.

DESCRIPTION OF THE DRAWING

Other characteristics and advantages may be gathered from the followingdescription, with reference to the accompanying diagrammatic drawingwhich illustrates by way of example the various elements of an applianceaccording to the invention with occlusal fastening and in which:

FIG. 1 is a conventional diagrammatic view of the teeth of the maxillaryand mandibular arches which are equipped with an appliance of the priorart,

FIG. 2 is a partial perspective view from the front of an applianceaccording to the invention, when it is put in place on the two dentalarches,

FIG. 3 is a partial side view showing the incisors equipped with theirhousings,

FIG. 4 is a front view of the maxillary incisor of FIG. 3,

FIG. 5 is a partial side view showing the canines equipped with theirhousings,

FIG. 6 is a front elevation view of the maxillary canine of FIG. 5,

FIG. 7 is a perspective view showing, on an enlarged scale, a housingfor a maxillary canine, equipped with an axial straightening device,

FIG. 8 is a partially sectional side view of the housing of FIG. 7,

FIG. 9 is a perspective view similar to FIG. 7, but showing the elementsof the straightening device when they are in the straighteningsituation,

FIG. 10 is a side elevation view of a mandibular premolar equipped withits housing,

FIG. 11 is a front elevation view of a tying ring equipped with itsmanipulating handle,

FIGS. 12 to 14 are side elevation views showing different phases in thetying of an arch wire to a maxillary incisor by means of the ring ofFIG. 11,

FIG. 15 is an elevation view of a cluster carrying several tying rings,

FIG. 16 is a side elevation view of a molar equipped with its housing,

FIG. 17 is a perspective view of an arch wire with bilateraldistalization,

FIG. 18 is a side elevation view of a set of teeth which is equippedwith the appliance having the bilateral distalization arch wire of FIG.17,

FIG. 19, is a perspective view of an embodiment of a gage forpositioning a housing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

It is customary, according to the international standards relating tothe representation of the two in each case maxillary and mandibulardental arches, to distribute the teeth in four quadrants delimited bythe occlusal plane PO and by the sagittal plane PS, as shown in FIG. 1,and to assign to each quadrant a numbering which starts from a newdecade, with this decade being assigned a unit corresponding to theposition of the tooth relative to the sagittal plane. Thus, in themaxillary arch, the central incisors are designated 11 and 21, thelateral incisors 12 and 22, the canines 13, 23, the first premolars 14,24, the second premolars 15, 25, the first molars 16, 26 and the secondmolars 17 and 27, the teeth of the mandibular arch being designated from31 to 37, 41 and 47, as shown in FIGS. 1 and 2, where the representationof the teeth stops at the premolars in FIG. 1 and at the first molars inFIG. 2.

Due to this conventional numbering, in the following description thecorresponding references to the elements of the invention will benumbered from 50.

The appliance according to the invention is therefore composed ofhousings B, of arch wires with optional sleeves C, forming part of aseries of a plurality of arch wires, of tying means E which can be seenin FIGS. 11 to 15, of a means F for positioning the ends of the archwires, as can be seen in FIG. 16, and of distalization means G shown inFIGS. 17 and 18.

According to the invention, and as shown in FIGS. 3 to 6, each housing Bfor the incisors, canines and premolars is composed of a base 50 makingit possible to fasten said housing by gluing to the anterior face of thetooth, of an anterior wall 51 and of an intermediate bridge 52. Thehousing is produced from a metal alloy and may comprise, on the outeranterior face of the wall 51, a ceramic pad 53 of the color of ivory ormatching the coloration of the teeth. In the intermediate bridge 52 ismade a groove 54 of rectangular cross section which issues in thedirection of the occlusal plane, that is to say downward with regard toa housing for the maxillary arch and upward with regard to a housing forthe mandibular arch. The intermediate bridge 52 likewise comprises, onthe one hand, between the base 50 and the groove 54, an anchoring flute55 issuing on the same side as the groove 54 and, on the other hand,between the base 50 and the wall 51, a groove 56 issuing opposite thegroove 54. FIGS. 3 to 6 clearly show that the anterior wall 51, seenfrom the front, has a square or trapezoidal shape and has a width and aheight greater than those of the bridge 52 and of the base 50 so as tomask these two parts, that is to say conceal them from view. As shownmore particularly in FIGS. 5 and 6, each of the housings for the caninesand the premolars comprises, furthermore, a vertical spur 57 whichprojects from the wall 51 on the opposite side to the groove 54, that isto say on the opposite side to the occlusal plane of the mouth.

The groove 54, made in each housing, has a rectangular cross sectionallowing it to receive arch wires of round or square cross section, butalso an arch wire of rectangular cross section, the small sides 58 ofwhich are parallel to the occlusal plane, as shown in FIG. 3. It shouldbe noted that, when the arch wire is engaged in the groove 54, theforces of reaction to the clamping of the teeth by the arch wire, saidforces tending to cause this arch wire to bend, have no effect on thiswire in its part included in the groove 54 of each housing B, since theyare countered by the wall 51. The result of this is that thestraightening forces imparted to the teeth by the arch wire are utilizedmuch more effectively than in housings comprising a horizontal grooveissuing to the front and thus making it possible to reduce the treatmenttime. The correction of the axial dental rotations is therefore highlyeffective.

FIGS. 7 to 9 show a therapeutic aid which can be used for treatingcomplex pathologies for which the straightening afforded by the housingswould prove inadequate in spite of the good housing/arch-wireconnection.

In this embodiment, each housing for the canines and for the maxillarypremolars is associated with straightening means D and comprises, in itsintermediate part 52, a vertical through well 59 issuing into thehorizontal groove 54 and, more specifically, into a semicircular flute60 made in the bottom of this groove. The well 59 is cylindrical and hasa diameter slightly greater than the outside diameter of the wireforming a kickover spring 62 which comprises a vertical branch 63 and abranch 64. The branches 63 and 64, at rest, form an angle u having avalue of between 60 and 90°. The free end of the branch 64 is bent at 64a and folded to form a hook 65. When such a housing is placed on amaxillary canine 13 which has to be subjected to axial straightening, assoon as the connection between the housing and the tooth is sufficientthe branch 63 of the spring is introduced vertically into the well 59until the turn 61 of the spring 62 comes into abutment on the bottom ofthe groove 56. From that situation, the straightening of that part ofthe branch 63 which projects from the well 59 causes the folding of thispart and its engagement in the flute 60 of the housing, thus ensuringthe connection of the kickover spring 62 to this housing. After the archwire C has been put in place, in order to impart a straightening torqueto the housing and to the tooth it is sufficient for the branch 64 to bebrought closer to the branch 63, until the hook 65 comes above the archwire C, and then to release the branch 64 in such a way that this hookhooks onto the arch wire, as shown in FIG. 9.

It will be noted that, in this configuration, with the exception of themetal branch 64, all the other elements of the straightening means areconcealed behind the wall 51 of the housing.

FIG. 10 shows that, with regard to the maxillary and mandibularpremolars, the intermediate bridge 52 and the anterior wall 51 areshifted in the direction of the root of the tooth in relation to theirbase 50 a which is then wider. This eliminates the risks of occlusalinterference with the premolars facing one another and gives the housingbetter stability by changing the level and height of the gluing of itsbase to the tooth. The jutting of the base 50 a, which is of smallamount, has little influence on the general esthetic appearance of theappliance, the more so because the housing in question can scarcely beseen.

Finally, FIG. 16 shows that each housing for the molars is composed of abase 50 b, from which projects a step 67, through which passes a tunnel68 having a cross section of the same shape and dimensions, apart fromthe functional play, as those of the arch wire having the maximumtransverse dimensions. The step is also integral with a gingival hook 69making it possible to attach a conventional inter-maxillary connection.

In a known way, and as shown in FIG. 4, in each of the housings thusdescribed, the midplane P1 of the housing, hence of the groove 54,forms, relative to the midplane P2 of the tooth onto which it has to beplaced, an angle V having a variable value, depending on the teeth.Likewise, as shown in FIGS. 5 and 16, the midplane P3 of the groove 54or of the tunnel 68 forms, relative to the midplane P4 of the tooth, anangle T, the value of which varies, depending on the tooth in question.

The accompanying table indicates by way of example the values given tothese various angles for each of the housings, with a reminder of thecharacteristics of each housing.

The appliance is put in place by first gluing the housings to the frontface of the teeth in question, either as having to be oriented or so asto serve as a support. This gluing is preceded by accurate positioningwhich is carried out by means of a positioning gage designated as awhole by 88 in FIG. 20.

This gage consists of a bar 89 which, made of sterilizable material,comprises, projecting from at least one of its end faces 90, a spatula91 for bearing on the top of a tooth. The spatula 91 is associated witha blade 92 which is parallel to it and which comprises a part 92 aprojecting from the bar and a part 92 b engaged in a slideway 93 of thisbar. The blade is produced from sterilizable transparent syntheticmaterial. It is interchangeable and, where appropriate, can bediscarded.

If appropriate, a screw 94 ensures that said blade is fixed to the bar.The blade end face 95, which is set back from that of the spatula 91,comprises a horizontal line 96 which is colored or not. The distance 1between the line 96 and the face 91 a of the spatula 91 is, of course,adapted to the housing B which, in turn, is specific to a type of tooth.The value of 1 is, for example:

3.5 mm for the maxillary lateral incisors and the second premolars,

4 mm for the maxillary and mandibular central incisors and for the firstpremolars,

4.5 mm for the mandibular canines,

and 5 mm for the maxillary canines.

To reduce the number of gages, each bar 89 comprises, at each of itsends, a spatula 91/blade 92 assembly suitable for a positioningmeasurement. Thus, two bars are sufficient for ensuring the fourpositioning measurements of all the housings.

To position a housing B12 on a maxillary lateral canine 12, this housingis previously provided, on its anterior face, with an erasable crossformed by a vertical stroke 97 and a horizontal stroke 98. After theglue for fastening the housing to the tooth has been put in place andwhile this glue still allows the housing to be displaced, the latter isfirst positioned transversely, by its vertical stroke 97 being broughtsubstantially into the vertical midplane of the tooth, and is thenpositioned vertically by means of the gage 88.

After the spatula 91 has been placed onto the tooth, the orthodontistdisplaces the housing until its horizontal stroke 98 coincides with theline 96 of the blade. This adjustment is made easier by the fact thatthe blade 92 is transparent. At this stage, the positioning gage isremoved.

When all the elements are positioned and fastened, the ties E are put inplace, and then the arch wires C are introduced first into the tunnels68 of the housings fastened to the molars and then into the horizontalgrooves 54 of each of the housings. This engagement is carried out veryeasily, whatever the cross sections of the arch wire used and theelasticity of the branches of this wire. This arrangement takes placefrom the bottom upward with regard to the maxillary housings and fromthe top downward as regards the mandibular housings. When the mandibularwires are fitted, if the appliance comprises straightening means D, thehooks 65 are put in place and then tying means are fitted.

In order to make this putting in place easier and according to onecharacteristic of the invention, each tying ring 70, which is producedfrom elastic synthetic material, for example from elastomer, is integralwith a gripping handle 71, to which it is connected by means of abreakable zone 72. This assembly is supplied in the form of a cluster 73composed of a main branch 74, on either side of which are arrangedtransversely the handles 71 connected to this branch by means ofbreakable zones 75.

As a result of this arrangement, each ring 70 can be gripped very easilyby its handle 71 in order to be detached from the cluster 73 and bebrought around the intermediate bridge 52 and into the grooves 56 and 55of each housing in question, as shown in FIG. 12, this taking placebefore the arch wire C is put in place. After this arch wire has beenput in place, and as shown in FIG. 13, the orthodontist can, withoutdifficulty, by grasping the gripping handle 71, cause the ring 70 topivot about the arch wire C in order to attach its loop, up to then atthe bottom, in the groove 56, as shown in FIGS. 13 and 14, thus forminga double tie. As soon as the tie is completed, the handle 71 isseparated from the ring by the severing or breaking of the zone 72. FIG.14 shows that the ring 70 is inserted completely behind the wall 51.

This tie, having a double passage, forms two loops which, arranged oneither side of the bridge 52, surround the parts of the wire whichemerge from the groove 54. These loops ensure that the wire is wedged interms of vertical translation against the bottom of the groove 54, iswedged in terms of horizontal translation against one of the verticalwalls of the groove, if there is play, and is wedged in terms oflongitudinal translation. Thus, the arch wire C is connected to thehousing firmly and positively, so that the latter cannot pivot relativeto this wire. The result of this is that the straightening force canimpart to the tooth only a translational force parallel to itself whichis conducive to straightening.

The arch wires may be made of steel or of any other alloy combiningnickel and titanium or titanium and molybdenum, in the same way as inform memory alloys or composite material. Advantageously, in the gapsbetween housings, they receive sleeves made of synthetic material whichhave the color of the teeth. Under these conditions, the entire frontpart of the appliance has the color of the teeth and considerablyimproves the esthetic appearance of the mouth.

As an example, the arch wires have, depending on their cross section,the following dimensions expressed in millimeters:

round cross section; diametral dimension 0.304 mm; 0.355 mm; 0.406 mm;0.457 mm and 0.508 mm

square cross section: 0.508 mm×0.508 mm and 0.558 mm×0.558 mm

rectangular cross section for vertical insertion with the narrow sidehorizontal: 0.558 mm×0.406 mm; 0.635 mm×0.482 mm and 0.635 mm×0.508 mm.

In an embodiment shown in FIGS. 17 and 18, the maxillary arch wireintended for ensuring bilateral distalization comprises, on each of itsbranches 80, a helical spring 82 which is arranged around said branch.Each spring is fixed to the branch by means of a weld 83 of its anteriorend. This weld is made in that zone of the branch which is set back fromthe canines. This arch wire also comprises a vertical hook 84 whichprojects toward the top of the branch part which comes between theincisor and the lateral canine. The position of the spurs on thebranches 80 depends on the patient's morphology as does, moreover, theposition of the stop welds 83. In other words, this type of arch wire issupplied in several models which differ in the shape of the arc and inthe position of the hooks 84 and of the welds 83.

This arch wire for active distalization is used in a first treatmentstage for distalizing the molars and the canines. It implies that thepremolars are not provided with any housing, as shown with regard tothose 14 and 15 in FIG. 18. This figure also shows that this arch wireis employed with a maxillary arch comprising on the molar 16 a housingB16 and on the mandibular arch housings B46 and B47 of the typeillustrated in FIG. 16. The maxillary arch is equipped with a housingfor a canine B13, of the type illustrated in FIGS. 5 and 6.

When the two arch wires are positioned, two elastic intermaxillarytraction ties are put in place on each side of the appliance, to beprecise a tie 85 extending from the hook 84 to the hook 69 of thehousing B46 and a tie 86 extending from the hook 57 of the housing B13fastened to the canine to a hook 69 of a housing B47 fastened to themolar 47. The arch wire is subjected by these ties to a tensile force inthe direction of the arrow 87 which brings the free end of its spring 82to bear under compression against the step 67 of the housing B16 andthus imparts a distalizing force to the molar 16. This originalmechanism for distalizing the teeth avoids the orthodontic extractionsof healthy premolars normally prescribed to make room posteriority inpatients who have “protruding teeth”.

Although this device is partially visible in the first treatment phase,it is much less demanding for the patient than an extra-oral applianceand, in particular, an appliance with pericranial support.

It may be gathered from the foregoing that the appliance according tothe invention not only makes the practitioner's work easier and improvesthe esthetic appearance of the patient, but also, by virtue of the highstability of the arch wires in the housings, improves the straighteningof the teeth and consequently makes it possible to reduce the treatmenttime, while at the same time improving dental hygiene.

Table of the individual technical characteristics of the housingsAngulation Axial under angulation Horizontal torsion T V Housingsangulation Maxillary teeth Central incisors 11 and 21  22° +5°  Simplehousing No Lateral incisors 12 and 22  14° +8°  Simple housing NoCanines 13 and 23  5° +10°  Simple housing + straightening No spring 1stpremolars 14 and 24  0° 0° Simple housing No 2nd premolars 15 and 25 −7° 0° Simple housing No 1stt molars 16 and 26 −10° 0° Tunnel + hook10° 2nd molars 17 and 27 −10° 0° Tunnel + hook  6° Mandibular teethCentral incisors 31, 32,  −6° 0° Simple housing No 41, 42 Lateralincisors 33 and 43  −7° +6°  Simple housing No 1st premolars 34 and 44−11° 0° Simple housing No 2nd premolars 35 and 45 −17° −3°  Simplehousing No 1st molars 36 and 46 −22° −6°  Cast tunnel + hook  6° 2ndmolars 37 and 47 −27° −10°  Cast tunnel + hook 10°

What is claimed is:
 1. An orthodontic dental kit which, for each in eachcase maxillary and mandibular dental arch, comprises: a series of archwires forming a U-shaped arc, adaptable to surround each dental arch anddiffering from one another in the straightening forces which theirbranches supply, said wires having a rectangular cross section withtheir small sides parallel to the occlusal plane, metal housingsadaptable to be fastened by their base being glued to the incisors,canines and premolars and comprising a horizontal groove for receivingthe arch wire, said groove issuing in the direction of the occlusalplane and being formed in an intermediate bridge connecting the base toan anterior wall, metal housings adaptable to be fastened by gluing tothe molars and comprising a tunnel for positioning the end of thecorresponding branch of the arch wire, ties, for tying the arch wire inthe grooves of the housings, and means imparting, at least to themaxillary arch wire and in one treatment phase, a tensile force directedtoward the rear, wherein each of the housings for the incisors, caninesand premolars comprises, for connecting to the arch wire, and in theintermediate bridge, on one side, between the base and the groove forthe arch wire, an anchoring flute issuing in the direction of theocclusal plane and, on the other side, between the base and the anteriorwall, a horizontal groove issuing opposite the groove for the arch wire,while the anterior wall has a width and a height greater than those ofthe base and those of the intermediate bridge, in order to mask thisbridge and the connection to the arch wire.
 2. The appliance as claimedin claim 1, wherein the connection is by an elastic ring.
 3. Theappliance as claimed in claim 2, wherein the tie formed by the elasticring comprises two loops surrounding the parts of the arch wire whichproject longitudinally from the intermediate bridge, and these loops areobtained as a result of the elastic ring being put in place around theintermediate bridge in the flute and in the groove of the housing, then,after the introduction of the arch wire into the groove, of the ringbeing pivoted around the arch wire for the purpose of attaching its loopcoming from the flute in the opposite groove.
 4. The appliance asclaimed 2, wherein the elastic ring is made of elastomer and isconnected by a breakable zone to a manipulating handle, itself connectedby a breakable zone to the central branch of a cluster, said clusterbeing composed of a plurality of handle/ring assemblies distributed oneither side of its central branch.
 5. The appliance as claimed in claim1, wherein each housing for the canines and premolars comprises, in itspart between the base and the anterior wall, a vertical well issuinginto the groove for the arch wire and forming, with a flute made in thebottom of said groove, an anchoring member for the bent end of one ofthe branches of a kickover spring for the axial straightening of thetooth, the other branch of this spring being provided with an end hookhooking onto the arch wire.
 6. The appliance as claimed in claim 1,wherein the anterior face of the anterior wall of each housing for theincisors, canines and premolars is covered by a pad having a color closeto that of the teeth.
 7. The appliance as claimed in claim 6, whereineach of the in each case maxillary and mandibular arch wires issurrounded, in the gaps between housings, by sleeves made of syntheticmaterial having the color of the teeth.
 8. The appliance as claimed inclaim 1, which comprises a maxillary arch wire for the bilateraldistalization of the molars and canines, comprising on each of itslateral branches, on the one hand, a helical spring which is arrangedaround said branch and the anterior end of which is connected to thisbranch by means of a weld arranged on a zone of this branch which is setback from the canine, while the posterior end of this spring comes tobear on the housing of the molar to be straightened, and, on the otherhand, a vertical hook which, projecting upward and from that part of thebranch which comes between the lateral incisor and the canine, forms anattachment means for one of the ends of an elastic intermaxillarytraction ring, the other end of which is attached to the hook of thehousing fastened to the corresponding first mandibular molar.
 9. Theappliance as claimed in claim 1, wherein each housing comprises, on itsanterior face, an erasable centering cross composed of a vertical strokeand of a horizontal stroke and capable of cooperating with a positioninggage, while said gage is composed, on the one hand, of a bar, at leastone of the end faces of which is prolonged by a spatula for bearing onthe tooth, and, on the other hand, of an interchangeable blade which,parallel to the spatula, is shorter than the latter, projects from thesame end face, is produced from a transparent material and comprises, onits end face, a horizontal line for positioning the horizontal stroke ofthe housing.